9 research outputs found
Effects of halo substructure on the power spectrum and bispectrum
We study the effects of halo substructure and a distribution in the
concentration parameter of haloes on large-scale structure statistics. The
effects on the power spectrum and bispectrum are studied on the smallest scales
accessible from future surveys. We compare halo-model predictions with results
based on N-body simulations, but also extend our predictions to 10-kpc scales
which will be probed by future simulations. We find that weak-lensing surveys
proposed for the coming decade can probe the power spectrum on small enough
scales to detect substructure in massive haloes. We discuss the prospects of
constraining the mass fraction in substructure in view of partial degeneracies
with parameters such as the tilt and running of the primordial power spectrum.Comment: 9 pages, 10 figures; replaced with version published in MNRAS;
removed grey-scale versions of figures which were being included at the end
by the serve
Baryon Oscillations and Dark-Energy Constraints from Imaging Surveys
Baryonic oscillations in the galaxy power spectrum have been studied as a way
of probing dark-energy models. While most studies have focused on spectroscopic
surveys at high redshift, large multi-color imaging surveys have already been
planned for the near future. In view of this, we study the prospects for
measuring baryonic oscillations from angular statistics of galaxies binned
using photometric redshifts. We use the galaxy bispectrum in addition to the
power spectrum; this allows us to measure and marginalize over possibly complex
galaxy bias mechanisms to get robust cosmological constraints. In our parameter
estimation we allow for a weakly nonlinear biasing scheme that may evolve with
redshift by two bias parameters in each of ten redshift bins. We find that a
multi-color imaging survey that probes redshifts beyond one can give
interesting constraints on dark-energy parameters. In addition, the shape of
the primordial power spectrum can be measured to better accuracy than with the
CMB alone. We explore the impact of survey depth, area, and calibration errors
in the photometric redshifts on dark-energy constraints.Comment: 17 pages, 12 figure
Dark energy and substructure effects on the large -scale structure
I consider in detail how the large-scale structure of the universe can provide information about two topics of current interest in cosmology: the nature of dark energy and the abundance of substructure in dark matter halos. Baryonic oscillations in the galaxy power spectrum have been studied as a way of probing dark energy models. While most studies have focused on spectroscopic surveys at high redshift, large multicolor imaging surveys have already been planned for the near future. In view of this, I consider the prospects for measuring baryonic oscillations from angular statistics of galaxies binned using photometric redshifts. I use the galaxy bispectrum in addition to the power spectrum; this allows one to measure and marginalize over possibly complex galaxy bias mechanisms to get robust cosmological constraints. I find that a multicolor imaging survey that probes redshifts beyond unity can give interesting constraints on dark energy parameters. In addition, the shape of the primordial power spectrum can be measured to better accuracy than with the cosmic microwave background alone. In the second example I consider the effects of halo substructure on large-scale structure statistics. The effects on the power spectrum and bispectrum are studied on the smallest scales accessible from future surveys. We compare halo model predictions with results based on N-body simulations, but also extend our predictions to 10 kpc scales which will be probed by future simulations. We find that weak-lensing surveys proposed for the coming decade can probe the power spectrum on small enough scales to detect substructure in massive haloes. We discuss the prospects of constraining the mass fraction in substructure in view of partial degeneracies with parameters such as the tilt and running of the primordial power spectrum
Universal Solvation Model Based on Conductor-Like Screening Model
ABSTRACT: Atomic surface tensions are parameterized for use with solvation models in which the electrostatic part of the calculation is based on the conductor-like screening model (COSMO) and the semiempirical molecular orbital methods AM1, PM3, and MNDO/d. The convergence of the calculated polarization free energies with respect to the numerical parameters of the electrostatic calculations is first examined. The accuracy and precision of the calculated values are improved significantly by adjusting two parameters that control the segmentation of the solvent-accessible surface that is used for the calculations. The accuracy of COSMO calculations is further improved by adopting an optimized set of empirical electrostatic atomic radii. Finally, the electrostatic calculation is combined with SM5-type atomic surface tension functionals that are used to compute the nonelectrostatic portions of the solvation free energy. All parameterizations are carried out using rigid (R) gas-phase geometries; this combination (SM5-type surface tensions, COSMO electrostatics, and rigid geometries) is called SM5CR. Six air–water and 76 water–solven
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Efficacy and safety of two neutralising monoclonal antibody therapies, sotrovimab and BRII-196 plus BRII-198, for adults hospitalised with COVID-19 (TICO): a randomised controlled trial
We aimed to assess the efficacy and safety of two neutralising monoclonal antibody therapies (sotrovimab [Vir Biotechnology and GlaxoSmithKline] and BRII-196 plus BRII-198 [Brii Biosciences]) for adults admitted to hospital for COVID-19 (hereafter referred to as hospitalised) with COVID-19.
In this multinational, double-blind, randomised, placebo-controlled, clinical trial (Therapeutics for Inpatients with COVID-19 [TICO]), adults (aged ≥18 years) hospitalised with COVID-19 at 43 hospitals in the USA, Denmark, Switzerland, and Poland were recruited. Patients were eligible if they had laboratory-confirmed SARS-CoV-2 infection and COVID-19 symptoms for up to 12 days. Using a web-based application, participants were randomly assigned (2:1:2:1), stratified by trial site pharmacy, to sotrovimab 500 mg, matching placebo for sotrovimab, BRII-196 1000 mg plus BRII-198 1000 mg, or matching placebo for BRII-196 plus BRII-198, in addition to standard of care. Each study product was administered as a single dose given intravenously over 60 min. The concurrent placebo groups were pooled for analyses. The primary outcome was time to sustained clinical recovery, defined as discharge from the hospital to home and remaining at home for 14 consecutive days, up to day 90 after randomisation. Interim futility analyses were based on two seven-category ordinal outcome scales on day 5 that measured pulmonary status and extrapulmonary complications of COVID-19. The safety outcome was a composite of death, serious adverse events, incident organ failure, and serious coinfection up to day 90 after randomisation. Efficacy and safety outcomes were assessed in the modified intention-to-treat population, defined as all patients randomly assigned to treatment who started the study infusion. This study is registered with ClinicalTrials.gov, NCT04501978.
Between Dec 16, 2020, and March 1, 2021, 546 patients were enrolled and randomly assigned to sotrovimab (n=184), BRII-196 plus BRII-198 (n=183), or placebo (n=179), of whom 536 received part or all of their assigned study drug (sotrovimab n=182, BRII-196 plus BRII-198 n=176, or placebo n=178; median age of 60 years [IQR 50–72], 228 [43%] patients were female and 308 [57%] were male). At this point, enrolment was halted on the basis of the interim futility analysis. At day 5, neither the sotrovimab group nor the BRII-196 plus BRII-198 group had significantly higher odds of more favourable outcomes than the placebo group on either the pulmonary scale (adjusted odds ratio sotrovimab 1·07 [95% CI 0·74–1·56]; BRII-196 plus BRII-198 0·98 [95% CI 0·67–1·43]) or the pulmonary-plus complications scale (sotrovimab 1·08 [0·74–1·58]; BRII-196 plus BRII-198 1·00 [0·68–1·46]). By day 90, sustained clinical recovery was seen in 151 (85%) patients in the placebo group compared with 160 (88%) in the sotrovimab group (adjusted rate ratio 1·12 [95% CI 0·91–1·37]) and 155 (88%) in the BRII-196 plus BRII-198 group (1·08 [0·88–1·32]). The composite safety outcome up to day 90 was met by 48 (27%) patients in the placebo group, 42 (23%) in the sotrovimab group, and 45 (26%) in the BRII-196 plus BRII-198 group. 13 (7%) patients in the placebo group, 14 (8%) in the sotrovimab group, and 15 (9%) in the BRII-196 plus BRII-198 group died up to day 90.
Neither sotrovimab nor BRII-196 plus BRII-198 showed efficacy for improving clinical outcomes among adults hospitalised with COVID-19.
US National Institutes of Health and Operation Warp Spee